Camber angle is a measure of how much a wheel or tire on a vehicle leans or tilts, either inward toward or outward from the vehicle, when viewed from the front or back of the vehicle. As such, the camber angle can be defined in different ways by measuring the relative positions of various components on a vehicle. FIGS. 1A and 1B illustrate one example of a measurement of the camber angle, which is defined by the angle between a vertical line and a wheel centerline as viewed from the front of the wheel. The camber angle illustrated in FIGS. 1A and 1B can also be defined as positive or negative. As shown in FIG. 1A, an outward tilt (away from the vehicle) of a top portion of the wheel results in a positive camber angle, and an inward tilt (toward the vehicle) of the top portion of the wheel results in a negative camber angle, as shown in FIG. 1B.
Caster angle is typically defined by the angle between a vertical line and a line drawn through upper and lower steering pivots, as viewed from either side of the vehicle. As such, the caster angle can also be defined in different ways by measuring the relative positions of various components on a vehicle. For example, the caster angle can be defined as the angle between a vertical line and a caster reference line drawn either through an upper strut mount and a lower ball joint or through an upper ball joint and the lower ball joint. FIGS. 2A and 2B illustrate one example of a measurement of the caster angle, which can also be defined as positive or negative. As shown in FIG. 2A, a forward tilt of the caster reference line results in a negative caster angle, and a rearward tilt the caster reference angle results in a positive caster angle, as shown in FIG. 2B. The caster and camber angles can be defined in various other ways in relation to other vehicle components, and should not be limited to the descriptions and illustrations provided herein.
Aspects of the present invention involve control arms and ball joint assemblies for use on motor vehicle suspension systems. Described and depicted herein are various configurations of control arms and ball joint assemblies that allow a user to make various adjustments to the caster and/or camber angles of the suspension system during wheel alignment.